The present invention relates generally to a night vision system and more particularly to a night vision system that is responsive to vehicle steering systems.
Night vision systems are utilized to allow a user to see objects at relatively low visibility light levels. Examples of night vision technologies are image enhancement and thermal imaging.
Image enhancement functions through collecting the tiny amounts of light, including the near infrared light spectrum, that are present but may be imperceptible to human eyes, and amplifying the light to a point at which the image can easily be observed.
Thermal imaging operates by capturing the far infrared light spectrum, which is emitted as heat by objects instead of simply reflected as light. Hotter objects, such as warm bodies, emit more of this light than cooler objects such as trees or buildings.
Night vision systems typically are classified as either passive or active. In known, passive, night vision systems used in automotive applications, far infrared cameras are used to image objects using the ambient infrared light emitted by the objects in the environment. Far infrared night vision systems have relatively few pixels and, accordingly, images formed using such cameras have low video resolution and a relatively narrow field of view. Known active night vision systems utilize a near-infrared (NIR) diode laser or a filtered incandescent light source. The NIR light is subsequently reflected off objects in the environment and is received by a camera. The camera generates a video signal responsive to received light.
Current night vision systems have a camera rigidly fixed in the vehicle pointing straight ahead. This arrangement works well if the vehicle remains relatively flat and steady while travelling in a straight line. However, this scenario is rarely achieved. Given that the camera is designed to focus beyond the range of the headlights, a pitch of a single degree can cause a shift of over twelve feet in the image. This can be distracting to a driver viewing a display of the imaged area on, for example, a Heads Up Display (HUD).
In addition, while on a curved road, the driver will be focusing, and the vehicle travelling, in a direction different than where the camera is pointing providing very little useful information to the driver.
The disadvantages associated with current night vision systems for automobiles have made it apparent that a new night vision system is needed. This new system should provide increased night vision information during most vehicle operating conditions including curves and hills.
In accordance with one aspect of the present invention, a night vision system for a vehicle is provided. The system includes a motion or directional sensor coupled to the vehicle and adapted to generate a vehicle directional signal when the vehicle is changing bearing (i.e. undergoing a turn, ascending or descending); a night vision camera adapted to generate a camera signal; a camera motor adapted to direct the night vision camera; and a camera motor control unit adapted to receive the vehicle directional signal from the directional sensor and respond by activating the camera motor.
In accordance with another aspect of the present invention, a night vision method for a vehicle is provided. The method includes sensing that the vehicle is changing bearing; generating a vehicle directional signal; activating a camera motor control unit adapted to direct a night vision camera in response to the vehicle directional signal; rotating the night vision camera; steadying an image from the night vision camera; and displaying the image on an image view screen.
The present invention enhances the utility of night vision systems far beyond present ranges of use by providing added night vision information during various vehicle operating conditions including turns. The aforementioned system directs the night vision camera while the vehicle is turning rather than having a constant view along the instantaneous direction of travel of the vehicle, as currently exists in the art.